When a user logs in to a remote computer, the remote computer needs to transfer its desktop content to a client by using remote desktop technology, and a local device of the client displays the desktop content of the remote computer. At present, most remote desktop systems transfer remote desktop contents via an Internet Protocol (IP) network. A remote desktop may include such technologies as desktop image display, remote sound transmission, or pluggable hardware mapping of a remote computer. A remote desktop is also known as a virtual desktop. In a virtual desktop scenario, at least one server and one client exist. Login to a remote server is implemented by using virtual desktop client software installed on the client.
A desktop image can be transferred to the client by using drawing instructions. For example, the client receives instructions, which are sent by the remote computer, such as “fill region XX with color XX”, “draw an XX-wide line with color XX from point XX to point XX”, or “draw image XX in position XX”. For the last drawing instruction, because it carries image information that occupies a bandwidth, the remote computer will, when sending the drawing instruction to the client, process the image according to a certain policy, for example, an image compression policy, to reduce the amount of data transferred between the remote computer and the client and reduce the bandwidth occupancy ratio. Which policy is used by the remote computer to process an image to be sent to the client mainly depends on an image recognition technology. The remote computer recognizes an image type, and determines a corresponding processing policy according to the image type. However, this technology depends on image type recognition by the remote computer. Determining an image processing policy according to the image type may result in image data transmitted to the client failing to meet client requirements. For example, after the remote computer performs a lossy compression on a recognized image and then transmits the image to the client for display, the image cannot meet the high image quality requirement of the client, which affects user experience.